Traffic in Turkey's Bosphorus Strait, an important international shipping lane for oil and grain, was suspended on Tuesday due to poor visibility and heavy rain, shipping agent GAC said.
It said shipping was suspended at 830 am (0530 GMT).
The Bosphorus is one of world's most important choke points for the maritime transit of oil, with over 3 percent of global supply - mainly from Russia and the Caspian Sea - passing through the 17-mile waterway connecting the Black Sea to the Mediterranean. It also carries large amounts of grains from Russia and Kazakhstan to world markets.
Turkish authorities also closed Dardanelles strait to tankers longer than 200 metres after an oil tanker ran aground. Traffic was expected to resume from 0730 GMT onwards GAC said.
Reporting by Can Sezer